This invention relates to a ventilation device which can automatically turn on, turn off, adjust the blowing time, direction and conditions of air while detecting the occurrence and position of human bodies in the area to be ventilated.
The indoor ventilation devices of conventional air conditioners or the ventilation devices of general purpose electric fans usually use a set of control blades which can be manipulated manually or automatically to adjust the blowing direction i.e., the direction in which air is discharge. The blowing direction, however, can not be modulated to follow along the movement of human body. In other words, the blowing direction either is fixed or keeps moving to and fro within a certain range. This may cause unnecessary power consumption when nobody is in the area to be ventilated, or only those in the area can air flow. When the power of an air conditioner or a cooler/heater is turned on, the indoor temperature in the area to be ventilated can not be evenly warmed up or cooled down immediately, and people who stay in the area may feel sudden cool or sudden warm as they walk around. It takes time and consumes energy to achieve uniform temperature in the entire area. Furthermore people may have their preferred temperatures and blowing conditions--that is, the fixed temperature and blowing strength can not meet their respective preferences. Economically, to save energy, it is not necessary to cool/warm the whole room. In fact, as long as the ventilation device follows the movements of human bodies and blows wind relating to people's preferred wind strengths, temperatures and (relative) humidities, the ventilation requirements are met. Even when there are several persons in the room, the ventilation device can blow wind (discharge air) toward them respectively, instead of purposelessly blowing wind with the same speed through the whole area. Additionally, the power of the ventilation device automatically turns on as people enter the room and turns off as they leave the room. The strength or intensity of the blowing that follows the movement of the human body varies with the person's preference and the distance from the wind source to the person. Thus the wind speed that reaches the position of the person is just what is required. Accordingly to the present invention operations are the above mentioned all automatic and fulfils the energy saving policy.
Moreover, the ventilation outlets of the conventional air conditioners are usually left open. When the air conditioner is not in use, the outlets collect dust and insects; and as the air conditioner is turned on the next time, the impurities will be blown out into the ventilated area and the user feels uncomfortable. Furthermore, if the impurities get into the heat exchanger, they will cause a negative effect on the efficiency of the heat exchanger. Thereby, it is necessary to close all the ventilation outlets while not in use to keep the air conditioner clean and efficient.